1. Field of the Invention
The present invention relates to a silicone hyper-branched polymer surfactant which includes both a hydrophobic functional group and a hydrophilic functional group. In addition, the present invention relates to a method of preparing the silicone hyper-branched polymer surfactant, and to a method of rinsing using a rinsing solution including the silicone hyper-branched polymer surfactant.
A claim of priority is made to Korean patent application No. 10-2003-0012825, filed Feb. 28, 2003, the entire contents of which are incorporated herein by reference.
2. Description of the Related Art
Generally, an integrated circuit is manufactured by forming desired circuit patterns on each layer of a chip circuitry using photolithography processes. Photolithography is characterized by the successive processes of exposure, development and etching with respect to a photoresist film formed of a photo-chemically reacting material.
The exposure process is carried out to transfer the pattern of a photo-mask to the photoresist film by passing light through a photo-mask having a desired mask pattern. When the photoresist film is formed of a negative photoresist material, exposed portions of the material undergo a chemical bonding to form a polymer which is less soluble than the non-exposed portions of the film. When the photoresist film is formed of a positive photoresist material, chemical bondings of exposed portions of the material are cleaved into unit molecules which make the exposed portions more soluble then the non-exposed portion. In each case, the photoresist film is patterned by the exposure process into soluble and non-soluble regions.
The developing process is carried out to remove the soluble portions of the photoresist film, with the result being a photoresist pattern formed over a substrate.
Finally, an etching process is implemented using the photoresist pattern as an etch mask to etch a layer formed on the substrate to obtain a desired pattern such as a wiring pattern. Here, the photoresist at the region in which the photochemicalreaction has been caused by the exposure should be completely removed through the developing process, thereby obtaining an accurate pattern of an underlying layer after completing the etching process. However, the photoresist at the region in which the photochemicalreaction has been caused frequently may be not completely removed, and instead residues may remain. This is particularly true in the case of patterns having high aspect ratios which are characteristic of highly integrated semiconductor devices.
Accordingly, a rinsing process is adopted in which deionized water is used as a rinsing solution to remove residual developing solution and the residual photoresist. However, since the residual photoresist is hydrophobic while the rinsing solution is hydrophilic, the residual photoresist may not be completely removed using the rinsing solution of deionized water. That is, the strongly hydrophobic residue is liable to re-attach between patterns during a drying process conducted after the rinsing process. This re-attached residue constitutes an impurity which can adversely impact later processes.
FIGS. 1A and 1B are cross-sectional views of a semiconductor device obtained after implementing a general developing process and a rinsing process.
Referring to FIG. 1A, a photoresist pattern 130 is formed after completing a developing process. Residues 150 that have not been dissolved into a developing solution are formed on the surface portion of an exposed region and a non-exposed region of the photoresist pattern 130, and on the side portion of the photoresist pattern.
Referring to FIG. 1B, the non-dissolved residues 150 precipitate during a rinsing process because of a change of pH of the rinsing solution by deionized water. Accordingly, precipitate 170 is not removed through the rinsing process, but is instead adsorbed on the surface portion of the photoresist pattern to generate an impurity.
Meanwhile, during rinsing of the residues of the photoresist coated on a semiconductor substrate, a tailing and a flowing phenomenon of a partially dissolved photoresist may be generated. Also, during rinsing of residues of the photoresist coated on a semiconductor substrate, a photoresist attack (e.g., partial corrosion of the photoresist) may result when a rinsing solution having a high solubility with respect to a photoresist is utilized. Both tailing and photoresist attack may deteriorate the yield of a semiconductor device.